Community-acquired pneumonia (CAP) is a common reason for hospitalisation in childhood and represents a considerable socioeconomic burden. In hospitalised adults with CAP, we have shown a beneficial effect of short-term steroid treatment on time to clinical stability and on duration of hospital stay in a randomised controlled trial (RCT). These benefits in adults with CAP have been confirmed in a recent meta-analysis and appear to be independent of the aetiology of CAP. It is unclear if adjunct steroid treatment benefits children with CAP.Rationale: An intervention that shortens time to stability and discharge in childhood CAP would carry substantial socioeconomic benefits in terms of healthcare resource utilization as well as parental and child absenteeism from work and out-of-home activities, respectively. Based on our findings in adult patients with CAP, we expect a positive clinical effect of steroids also in children. So far, no large-scale RCTs have evaluated the effectiveness of oral steroids on patient-relevant or clinically relevant endpoints in childhood CAP. In particular, it is unclear whether clinical improvement in the short-term is offset by a mid-term increase in CAP recurrence. Aim of the study: The overall aim of the trial is to evaluate the impact of oral steroid treatment in children with CAP on outcomes that are of high importance for patients. Specifically, we aim to concurrently assess the effect of adjunct oral steroids in children hospitalised for CAP on clinical stability (efficacy) and CAP recurrence (safety).Objectives: The primary objective is to concurrently evaluate (i) whether treatment of children hospitalised for CAP with oral betamethasone is superior to placebo for clinical stability (defined as resolution of vital sign abnormalities in room air) within 48 hours of hospitalization; (ii) whether treatment of children hospitalised for CAP with oral betamethasone is noninferior to placebo for CAP-related readmissions to hospital within 28 days of randomisation. Other objectives include the evaluation of effects of oral betamethasone treatment (versus placebo) in children hospitalised for CAP on: duration of hospital stay; severity and duration of CAP symptoms; parental absence from work and/or child absence from routine out-of-home care or school; overall duration of antibiotic exposure and inpatient days; intensive care unit admissions; mortality; rate and severity of solicited clinical side effects and serious adverse events. Exploratory subgroup analyses are planned to evaluate the effect of age, initial antibiotic treatment, respiratory pathogen detected in initial nasopharyngeal swab and radiological evidence of CAP. Study Design: We propose a pragmatic randomised, controlled, patient-, care-giver-, investigator- and outcome-assessor blinded multicentre trial in 8 Swiss paediatric departments with two parallel groups (one active, one control; 1:1 ratio). Preschool and school-age children with moderate to severe CAP (defined clinically) requiring admission to hospital will be included. 700 patients will be randomised 1:1 to receive betamethasone (Betnesol®) (active group: 0.2 mg/kg/d in 1 daily dose for 2 days; control group: 2 days of placebo). The co-primary endpoints will be (i) the proportion of children who are clinically stable within 48 hours of randomisation; the proportion of children requiring CAP-related readmission to hospital within 28 days of randomisation. Significance: Any treatment associated with an increased likelihood of early clinical stability may lead to a higher proportion of children suitable for prompt discharge, in turn reducing the patient-relevant outcome of length of stay. This would likely lead to changes in paediatric CAP management in Switzerland (and similar high-income settings), especially if recurrence of moderate-severe CAP remained demonstrably low.